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Commit f0be3d32 authored by Lee Schermerhorn's avatar Lee Schermerhorn Committed by Linus Torvalds
Browse files

mempolicy: rename mpol_free to mpol_put 



This is a change that was requested some time ago by Mel Gorman.  Makes sense
to me, so here it is.

Note: I retain the name "mpol_free_shared_policy()" because it actually does
free the shared_policy, which is NOT a reference counted object.  However, ...

The mempolicy object[s] referenced by the shared_policy are reference counted,
so mpol_put() is used to release the reference held by the shared_policy.  The
mempolicy might not be freed at this time, because some task attached to the
shared object associated with the shared policy may be in the process of
allocating a page based on the mempolicy.  In that case, the task performing
the allocation will hold a reference on the mempolicy, obtained via
mpol_shared_policy_lookup().  The mempolicy will be freed when all tasks
holding such a reference have called mpol_put() for the mempolicy.

Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3b116300

include/linux/mempolicy.h

+5 −5
Original line number Diff line number Diff line
@@ -71,7 +71,7 @@ struct mm_struct; 
 *

 * Freeing policy:

 * Mempolicy objects are reference counted.  A mempolicy will be freed when

 * mpol_free() decrements the reference count to zero.

 * mpol_put() decrements the reference count to zero.

 *

 * Copying policy objects:

 * mpol_copy() allocates a new mempolicy and copies the specified mempolicy
@@ -98,11 +98,11 @@ struct mempolicy { 
 * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.

 */



extern void __mpol_free(struct mempolicy *pol);

static inline void mpol_free(struct mempolicy *pol)

extern void __mpol_put(struct mempolicy *pol);

static inline void mpol_put(struct mempolicy *pol)

{

	if (pol)

		__mpol_free(pol);

		__mpol_put(pol);

}



extern struct mempolicy *__mpol_copy(struct mempolicy *pol);
@@ -190,7 +190,7 @@ static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b) 
	return 1;

}



static inline void mpol_free(struct mempolicy *p)

static inline void mpol_put(struct mempolicy *p)

{

}

kernel/exit.c

+1 −1
Original line number Diff line number Diff line
@@ -967,7 +967,7 @@ NORET_TYPE void do_exit(long code) 
	proc_exit_connector(tsk);

	exit_notify(tsk, group_dead);

#ifdef CONFIG_NUMA

	mpol_free(tsk->mempolicy);

	mpol_put(tsk->mempolicy);

	tsk->mempolicy = NULL;

#endif

#ifdef CONFIG_FUTEX

kernel/fork.c

+1 −1
Original line number Diff line number Diff line
@@ -1374,7 +1374,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, 
	security_task_free(p);

bad_fork_cleanup_policy:

#ifdef CONFIG_NUMA

	mpol_free(p->mempolicy);

	mpol_put(p->mempolicy);

bad_fork_cleanup_cgroup:

#endif

	cgroup_exit(p, cgroup_callbacks_done);

mm/hugetlb.c

+1 −1
Original line number Diff line number Diff line
@@ -116,7 +116,7 @@ static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma, 
			break;

		}

	}

	mpol_free(mpol);	/* unref if mpol !NULL */

	mpol_put(mpol);	/* unref if mpol !NULL */

	return page;

}

mm/mempolicy.c

+13 −13
Original line number Diff line number Diff line
@@ -529,7 +529,7 @@ static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new) 
	if (!err) {

		mpol_get(new);

		vma->vm_policy = new;

		mpol_free(old);

		mpol_put(old);

	}

	return err;

}
@@ -595,7 +595,7 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags, 
	new = mpol_new(mode, flags, nodes);

	if (IS_ERR(new))

		return PTR_ERR(new);

	mpol_free(current->mempolicy);

	mpol_put(current->mempolicy);

	current->mempolicy = new;

	mpol_set_task_struct_flag();

	if (new && new->policy == MPOL_INTERLEAVE &&
@@ -948,7 +948,7 @@ static long do_mbind(unsigned long start, unsigned long len, 
	}



	up_write(&mm->mmap_sem);

	mpol_free(new);

	mpol_put(new);

	return err;

}
@@ -1446,14 +1446,14 @@ struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr, 
		nid = interleave_nid(pol, vma, addr, HPAGE_SHIFT);

		if (unlikely(pol != &default_policy &&

				pol != current->mempolicy))

			__mpol_free(pol);	/* finished with pol */

			__mpol_put(pol);	/* finished with pol */

		return node_zonelist(nid, gfp_flags);

	}



	zl = zonelist_policy(GFP_HIGHUSER, pol);

	if (unlikely(pol != &default_policy && pol != current->mempolicy)) {

		if (pol->policy != MPOL_BIND)

			__mpol_free(pol);	/* finished with pol */

			__mpol_put(pol);	/* finished with pol */

		else

			*mpol = pol;	/* unref needed after allocation */

	}
@@ -1512,7 +1512,7 @@ alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr) 
		nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);

		if (unlikely(pol != &default_policy &&

				pol != current->mempolicy))

			__mpol_free(pol);	/* finished with pol */

			__mpol_put(pol);	/* finished with pol */

		return alloc_page_interleave(gfp, 0, nid);

	}

	zl = zonelist_policy(gfp, pol);
@@ -1522,7 +1522,7 @@ alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr) 
		 */

		struct page *page =  __alloc_pages_nodemask(gfp, 0,

						zl, nodemask_policy(gfp, pol));

		__mpol_free(pol);

		__mpol_put(pol);

		return page;

	}

	/*
@@ -1624,7 +1624,7 @@ int __mpol_equal(struct mempolicy *a, struct mempolicy *b) 
}



/* Slow path of a mpol destructor. */

void __mpol_free(struct mempolicy *p)

void __mpol_put(struct mempolicy *p)

{

	if (!atomic_dec_and_test(&p->refcnt))

		return;
@@ -1720,7 +1720,7 @@ static void sp_delete(struct shared_policy *sp, struct sp_node *n) 
{

	pr_debug("deleting %lx-l%lx\n", n->start, n->end);

	rb_erase(&n->nd, &sp->root);

	mpol_free(n->policy);

	mpol_put(n->policy);

	kmem_cache_free(sn_cache, n);

}
@@ -1780,7 +1780,7 @@ static int shared_policy_replace(struct shared_policy *sp, unsigned long start, 
		sp_insert(sp, new);

	spin_unlock(&sp->lock);

	if (new2) {

		mpol_free(new2->policy);

		mpol_put(new2->policy);

		kmem_cache_free(sn_cache, new2);

	}

	return 0;
@@ -1805,7 +1805,7 @@ void mpol_shared_policy_init(struct shared_policy *info, unsigned short policy, 
			/* Policy covers entire file */

			pvma.vm_end = TASK_SIZE;

			mpol_set_shared_policy(info, &pvma, newpol);

			mpol_free(newpol);

			mpol_put(newpol);

		}

	}

}
@@ -1848,7 +1848,7 @@ void mpol_free_shared_policy(struct shared_policy *p) 
		n = rb_entry(next, struct sp_node, nd);

		next = rb_next(&n->nd);

		rb_erase(&n->nd, &p->root);

		mpol_free(n->policy);

		mpol_put(n->policy);

		kmem_cache_free(sn_cache, n);

	}

	spin_unlock(&p->lock);
@@ -2068,7 +2068,7 @@ int show_numa_map(struct seq_file *m, void *v) 
	 * unref shared or other task's mempolicy

	 */

	if (pol != &default_policy && pol != current->mempolicy)

		__mpol_free(pol);

		__mpol_put(pol);



	seq_printf(m, "%08lx %s", vma->vm_start, buffer);